Filter using transverse supporting means



Oct. 20, 1953 M, DOELZ 2,656,516

FILTER USING TRANSVERSE SUPPORTING MEANS Filed Aug. 14, 1952 19 18 1 4g 16 4 M v 5 1 ZZ 24 p 4 1a 20 w J INVENTOR. 6 M12 V/A/ l, 00:42

Patented Oct. 20, 1953 FILTER USING TRANSVERSE SUPPORTING MEANS Melvin L. Doelz, Glendale, Calif., assignor to lins Radio Company, Cedar Rapids, Iowa, a

corporation of Iowa Application August 14,1952, Serial No. 304,293

4 Claims.

This invention relates in general to mechanical filters and in particular to a drive system and support means for supporting a plurality of vibrating discs which are coupled together without substantially changing the frequency response.

The co-pending application entitled Mechanical Filters, Serial No. 248,011, filed September 24, 1951, illustrates a filter which is driven by a magnetostrictive coupling means that establishes mechanical vibrations and in which a magnetostrictive output means changes the mechanical vibrations of the filter to electrical signals.

It is an object of this present invention to provide a support for a filter such as described therein by transverse supporting means so as to prevent damping of the vibrations.

Another object of this invention is to provide a compact and highly efilcient electromechanical filter.

Further objects, features, and advantages of this invention will become apparent from the following description and claims when read in view of the drawings, in which:

Figure 1 is a top view 01. the filter of this invention with the cover member removed;

Figure 2 is a side view with the cover cut through;

Figure 3 is a sectional view taken on line 33 of Figure 2; and

Figure 4 is a sectional view taken on line 4-4 of Figure 3.

Figure 1 illustrates a base plate M which has mounted thereon stand-offs II and I2 that support hollow cylinders l3 and M, respectively. Polarizing magnets l8 and I! are supported by the stand-011's H and i2 adjacent the cylinders i3 and I4.

Four upright members l8, i3, and 2| are mounted to the base plate l0 between the standoffs H and I2 and a pair of transverse rods 22 and 23 are mounted between them. A plurality of discs 24 are connected together by coupling wires 26 attached to their peripheries. The end discs 21 and 28 have magnetostrictive input and output coupling wires 23 and 30 connected respectively to them. The rods 22 and 23 are connected to the edges of discs 21 and 28.

A pair of input leads 3| and 32 are connected to a driving coil 33 mounted within the cylinder l3. This is best shown in Figure 4. Likewise, a pair of output leads 34 and 35 are connected to an output coil mounted within the cylinder [4. The coupling wires 29 and 30 extend through the coupling coils.

A cover member 36 is connected to the base member [0. The base member In has a pair of mounting screws 3! and 38 which may be used to attach it to a chassis. The leads 3!, 32, 34, and 35 may be connected to suitable terminals 40 which extend through the base member Hi.

In operation, an electrical input signal is supplied to the leads 3| and 32 and if at the proper frequency, this causes the magnetostrictive driving rod 29 to excite the disc assembly. When this occurs the disc at the opposite end of the assembly vibrates and moves the output magnetostrictive rod 30 and this causes an electrical signal in the output coil which is connected to the leads 34 and 35.

Because of the flexibility of the transverse supporting rods 22 and 23, the end discs 21 and 28 will not be substantially damped but will oscillate at their natural resonant frequency. Thus. the entire disc assembly will resonate in a substantially undamped manner.

It is seen that this invention provides a new and novel means of mounting an electromechanical filter, such that very little damping occurs.

Although this invention has been described with respect to a particular embodiment thereof,

it is not to be so limited as changes and modifications may be made therein which are within the full intended scope of the invention, as defined by the appended claims.

I claim:

1. An electromechanical filter comprising, a base plate, a magnetostrictive driving means mounted on said plate, a magnetostrictive output means mounted on said plate, four upright members mounted on said plate, a first transverse rod extending between a pair of said upright members, a second transverse rod extending between the other upright members, a plurality of discs, a plurality of coupling wires attached to the peripheries of said discs, one end disc connected to the first transverse rod, the other end disc connected to the second transverse rod, and said magnetostrictive input and output means coupled to the end discs.

2. An electromechanical filter comprising, a base member, four upright members mounted on said base member, a pair of transverse rods extending respectively between pairs of said upright members, a disc assembly comprising a plurality of discs connected together by coupling Wires, the end discs of said disc assembly attached to said transverse rods, a magnetostrictive input means coupled to one of said input discs, and a magnetostrictive output means coupled to the other end disc.

3. An electromechanical filter comprising, a base member, a pair of stand-oils attached to the base member, a pair of coupling coils connected, respectively, to said stand-offs, four upright members mounted on said base member between said stand-offs, a pair of transverse rods extending transversely between pairs of said up right members, a plurality of metallic discs, one of said metallic discs connected to one of said transverse rods, a second disc connected to the other transverse rod, a plurality of coupling wires extending between the first and second discs and attached to their peripheries, a plurality of discs mounted to said coupling wires between said first and second discs, a magneto-strictive input wire connected to the first disc and extending through one of the coupling coils, and an output coupling wire attached to the periphery of the second disc and extending through the other coupling coil.

4. A magneto-strictive filter comprising, a base member, a disc assembly comprising a plurality of discs and a plurality of coupling wires attached to the peripheries of said discs to hold said disc in a parallel-spaced relationship, four upright members attached to said base plate, a first transverse rod extending between a first pair of said upright members, a second transverse rod extending between a second pair of said upright members, the periphery of one end disc attached to said first transverse rod, the periphery of the other end disc attached to the second transverse rod, magneto-strictive input means coupled to the one disc, and magneto-strictive output means coupled to the other end disc.

MELVIN L. DOELZ.

No references cited. 

